Happy Birthday, Yellowstone.

On this day 145 years ago, the world’s first national park, Yellowstone National Park, was created. For anyone who has visited this incredible land of fire and ice and marveled at the amazing wildlife and unique geologic features, there’s little doubt why Yellowstone is considered one of our nation’s greatest treasures. Even if you weren’t one of its more than 4 million visitors last year, you can still discover fun facts about the park.

1. Half the world’s (click here) hydrothermal features are found at Yellowstone. Yellowstone National Park preserves more than 10,000 hydrothermal features -- an extraordinary collection of hot springs, mudpots, fumaroles, travertine terraces and -- of course -- geysers. Microorganisms called thermophiles -- meaning “heat loving” -- live in these features and give the park its brilliant colors....